(1) Field of the Invention
The present invention relates to a method and device for folding and sealing sheets, and more particularly to a method and device for enhancing the security of information applied to a front side of a sheet by folding it face to face and sealing the folds along the lateral edges of the sheet so that the information is concealed and sealed inside said folds. In a preferred embodiment, address information is applied adjacent the trailing edge of the sheet, and the last fold leaves the address information exposed but conceals and seals the other information within said folds.
The present invention is designed to fold and seal one sheet of paper at a time. If the communication involves more than one sheet, each sheet or page will be folded separately.
(2) Description of the Prior Art
Devices for folding sheets are generally known in the prior art. For example, U.S. Pat. No. 3,516,665 to Schmeck, U.S. Pat. No. 3,510,122 to Gavaghan, and U.S. Pat. No. 3,416,785 to Sherman all show devices for folding sheets, which include feeding rollers for feeding a sheet, a buckle chute for receiving the sheet and causing it to buckle or bulge, and folding rollers for grasping the bulge in the nip thereof and creasing the sheet to fold it as the sheet is pulled through. A second buckle chute can be disposed after the folding rollers for receiving the folded edge of the sheet, bulging it a second time, and folding it by further rollers to form a second fold. U.S. Pat. No. 3,570,335 to Marin discloses a folding machine for paper sheets that includes a paperworking assembly for performing operations such as perforating, scoring, or slitting each folded sheet. However, these patents do not disclose the sealing of the folded sheet.
The use of adhesives to bind sheets together is also generally known. For example, U.S. Pat. No. 4,473,425 to Baughman et al. describes applying a line of adhesive to one surface of a sheet adjacent one side edge of the sheet as the sheet is moved along a path. A plurality of sheets are moved to an assembly station where they are jogged to align the sheets of the set. Pressure is then applied to the sheets over the line of adhesive to form a booklet, but this patent does not show the application of adhesive to the inside portions of a fold on a single sheet of paper for sealing the folds face to face of said single sheet.
Facsimile machines, such as the Pitney Bowes Model 8400, operate by receiving facsimile information which is reproduced onto a sheet of paper and which is then fed into a storage tray for retrieval. Other Pitney Bowes Facsimile machines are the models 8100, 8600, 8800, and 8900. Security may be a problem because the sheet is readily available for any passerby to read. This problem may be particularly acute where the information is received in off business hours, such as messages received in the United States from Europe in the early hours of the morning.
U.S. Pat. No. 4,321,703 to Schwaertzel et al. describes a transmission system for electronic transmission of in-house mail, which is said to fulfill security requirements that the transmitted documents in fact reach the properly designated recipient terminals. Yet this patent is not directed to ensuring the security of an information-bearing sheet once it has been deposited at the proper recipient terminal.